firefox@esr

Install command: 
brew install --cask firefox@esr

Names: Mozilla Firefox ESR, Mozilla Firefox Extended Support Release

Web browser

https://www.mozilla.org/en-US/firefox/all/#product-desktop-esr

Cask JSON API: /api/cask/firefox@esr.json

Cask code: firefox@esr.rb on GitHub

Current version: 140.3.1

Requirements: macOS >= 10.15

Conflicts with casks:

firefox 143.0.3 Web browser Mozilla Firefox
firefox@beta 144.0b8 Web browser Mozilla Firefox Beta
firefox@cn 116.0 Chinese version of Firefox firefox-cn

Analytics:

Installs (30 days)
firefox@esr 111
Installs (90 days)
firefox@esr 323
Installs (365 days)
firefox@esr 1,554